Low-Cost Scalable Radiative Cooling Membrane via Spray Fabrication for Sustainable Thermal Management

Area of Science:

• Materials Science
• Nanotechnology
• Sustainable Energy

Background:

• Radiative cooling is a passive thermal management strategy with potential for energy efficiency.
• High costs and manufacturing challenges limit the widespread adoption of radiative cooling technologies.

Purpose of the Study:

• To develop a cost-effective and scalable fabrication method for radiative cooling membranes.
• To evaluate the performance of a novel composite membrane for passive cooling applications.

Main Methods:

• A composite membrane was fabricated using a spraying technique with modified nano-zirconia and ethylene-octene copolymer (POE) on a polyethylene (PE) substrate.
• The membrane's hydrophobicity was characterized by water contact angle measurements.
• A cooling structure was assembled using the composite membrane on a polytetrafluoroethylene (PTFE) emitter and tested under field conditions.

Main Results:

• The composite membrane exhibited hydrophobic properties with a water contact angle of 100.6°.
• The cooling structure achieved a cooling power of 66.2 ± 4.3 W/m².
• Field tests demonstrated a daytime average cooling effect of 4.7 ± 0.3 °C, with a peak reduction of 3 ± 0.3 °C at noon.

Conclusions:

• The study successfully demonstrated a cost-effective and scalable spraying fabrication method for radiative cooling membranes.
• The developed composite membrane shows significant potential for passive cooling in buildings and enhancing energy efficiency.
• This advancement contributes to the commercial viability of radiative cooling technologies.